Light-emitting diodes (LEDs) are typically powered using transformer and rectifier circuitry. The rectifier(s), which can be part of an alternating current (AC) to direct current (DC) converter, may convert AC voltage levels (e.g., ±110V) to DC voltage levels (e.g., VDD and ground), and/or clip AC voltage levels to minimize the voltage amplitude (e.g., from the AC input voltage). The transformer may be used to change the rectified input voltage to a converted voltage (e.g., by a ratio based on the primary and secondary windings of the transformer) that is more suitable for the LED device. Typical control circuits for LEDs include analog-based “flyback” control that uses secondary winding feedback information to control certain functions of the LED device.
Drawbacks of secondary winding-based LED control can include higher costs and increased chip size due to use of an optical coupler (to translate an optical-based feedback signal from the LED to an electrical signal), reduced reliability associated with the optical coupler (due to the relatively high failure rate of optical couplers over time), and limited functionality when the flyback control circuitry includes purely analog circuits.